Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 681: | \[{5^{681}-1\over4}\] | 31 × 5449 × 9976651 × 67853479 × 608997871 × 863773591 × 17408515139<11> × 107857890714179<15> × 154907695140797990849<21> × 239976686263858506551<21> × 16831369699997499687405534401<29> × 114223618784447712095364474974480764422513325227090232439<57> × [3086958510395455119596806028927731613287891324340014505039778103085187424747945942121731383242740973159650862399273770061046702101019659239966614810162433813466446737894525308657797221245344521703683637015759700721631685393717937766300662979647717209125159816300163610113588136210048435931<289>] |